In southern areas of the United States and other countries which have intense sunshine, significant heat build-up occurs on the interiors of motor vehicles when such vehicles are parked in the sun. Much of this heat build-up results from the rays of the sun passing through the windshields of such vehicles. This occurs because of the relatively large size of vehicle windshields, and the fact that windshields typically slope backward at a substantial angle. In addition to producing heat build-up in the vehicle interior, the rays of the sun and the heat on the dashboard and upholstery tend to cause damage to these portions of the vehicle interior.
A variety of devices have been developed in the past to shield the interior of the vehicle against entry of the suns rays through the windshield when such a vehicle is parked. A highly popular and relatively simple device is in the form of an accordian-folded cardboard or plastic shield which is unfolded to stretch across the windshield interior To hold such a device in place, the sun visors then are moved to their lowered position to press against the inside of the shield, which, in turn, then is pressed into engagement with the windshield. When operation of the vehicle is desired, the sun visors are raised, and the corregated material is folded up. While these devices are relatively inexpensive, they are cumbersome to handle and wear out relatively quickly.
A variation of a folded corregated sield device is disclosed in the Patent to Klein #4,671,558. The device of this patent is a sheet made of a rollable single-face corregated fiberboard material. The Klein device requires attachment of a roller at one side of the vehicle windshield. When the shield is unrolled, it stretches across the windshield to provide the desired shielding action. As with the accordian-folded cardboard, the device is held in place at the top by lowering the sun visors to press against it.
Other devices have been developed in the form of roller shades, where the roller is attached either to the dashboard at the bottom of the window or at the top. Corresponding mating hooks or other attachment devices are secured on the opposite edge of the windshield. Such a device for the rear window of a hatchback vehicle is disclosed in the Patent to Dieterich #4,261,411. The construction of the shield of Dieterich is nearly identical to the conventional roller shades in common use in houses for many years. A disadvantage of the device of Dieterich is that the roller portion of the shade device must be fastened into the vehicle by means of screws or other attaching devices. Also, it is necessary for the roller to extend in a straight line or it will not operate. This tends to space the central part of the shade away from the window, since practically all motor vehicles currently being produced have rear windows and windshields which are concavely curved (as viewed from the inside).
Another approach which uses flexible fabric as a vehicular windshield curtain is disclosed in the Patent to Sarver #4,560,245. The device of this patent is simply a flexible, rectangular sheet of opaque fabric. Both the top and bottom edges of the fabric are provided with an elongated strip of one portion of a standard fabric hook and loop fastener. Corresponding strips of mating fastener materials are attached either to the dashboard or the bottom edge of the windshield, and also along the top edge of the windshield to fasten the fabric shield in place. The bottom edge normally remains secured. When the device is to be used, the fabric is raised, and the mating attaching material is secured along the top of the windshield to hold the device in place. Because a multiple point or continuous attachment across the entire width of the windshield is employed, installation and removal of the shield requires a person to press the fabric in place from one edge of the windshield to the other. In addition, a relatively unsightly strip of attaching material is clearly visible along the top of the windshield when the device is not in use. For this reason, many automobile owners object to such a device.
It is desirable to provide a shield for inhibiting the passage of heat and light through a vehicle windshield to the interior which overcomes the disadvantages of the prior art mentioned above and which also is effective in operation, easy to install, does not deface the vehicle interior, and is simple to use.